1. Field of the Invention
One embodiment of the present invention relates to a video-recording and transfer apparatus, which is mounted on a vehicle such as a train, records video data captured with an imaging device, and transfers, if necessary, to a video recording apparatus of the outside of the vehicle (a fixed wireless station or another vehicle), and relates to a video-recording and transfer method.
2. Description of the Related Art
With an increase in speed and a reduction in costs of a network technique, an Internet Protocol (IP) network has become widely used for transmission of video data, and a monitoring system using the IP network has become introduced for monitoring passenger compartments, passages and doors of trains.
In this monitoring system, IP cameras for monitoring installed at arbitrary positions are connected to the IP network, and the video data captured with each IP camera has been transmitted to video-record in a personal computer for viewing (PC for viewing) via the IP network. The PC for viewing functions as a video-recording and transfer apparatus of the video data.
In the PC for viewing, the recorded video is overwritten to be deleted without being viewed once if the day passed without accident; however, an object video is confirmed by the PC for viewing to record it on an external recording medium by using the PC for viewing, and the recording medium can be taken out if any accident has occurred.
Frequently, it is realized that an accident has occurred after a certain time interval, such as several hours or several dates, have passed. If the video of the inside of the train are desired to be recognized, it takes much time to retrieve the video to store it on the external recording medium and take out the medium, in a case where the train in operation, and in a case where the train is located at a distance place even if the train is stopped.
As mentioned above, it takes much time even if the object train is specified; however, in a case in which a plurality of trains is targeted, it takes greater deal of times For instance, when looking for a specified person, even if there is information that the person ought to ride the train due to depart at around 5 o'clock, there is a possibility for the person to ride any one of a plurality of trains due to depart at earlier or later than around 10 minutes. Meanwhile, in a case in which the specified person has made a train connection and the person still desired to be traced, it takes much more time. There may is a desire to prepare for a situation in which the PC for viewing on the train cannot be viewed owing to a breakdown of a network digital recorder (NDR, registered trademark in Japan).
Therefore, storing the recorded video of the NDR on the train in a server for video-recording at a railway station or a train base station has become desired highly. As an ideal, there is a method for installing a broadband wireless communication device on the train and for video-recording all the camera images on the train to simultaneously to store the images in the server at the railway station or the train depot through wire communications. This method may achieve high real-time processing; however, this method occupies a broadband through broadband wire communications (120 KB/s for one camera, 12 cameras for one car, 26 MB/s=207 Mbps in a case of a train consisting of 18 cars). The width of the band turns to an amount of a communication line usage fee as it is, so that this method may be adopted only in a case with no thought of profit.
As regards another method, a method, for each installing short-range high-rate wireless communication devices (millimeter-wave transmission, etc.) on a train and a platform, and transfers video data in the NDR mounted on the train through the communication devices, is a possible approach. However, to transfer the video data for a long while within a short stop time at a stop station, the method occupies a broadband as a communication path and burdens the NDR during video-recording with a heavy load, and then, the resulting affects on current video-recording with IP cameras. Depending on the stop time, there is a possibility that all the videos may not be transmitted within the stop time of the train.
As given above, the conventional video-recording and transfer apparatus mounted on the vehicle burdens the transfer of the video data with the heavy load and may affects on the current video-recording.